ROLE OF ANTIGEN DENSITY IN IMMUNE LYSIS OF INTERFERON-TREATED HUMAN LYMPHOID-CELLS - ANALYSIS WITH MONOCLONAL-ANTIBODIES TO THE HLA-A,B ANTIGENIC MOLECULAR-COMPLEX AND TO IA-LIKE ANTIGENS

Abstract

Cultured human lymphoid WI-L2 cells incubated with human leukocyte interferon (final concentration 500 and 2000 U/ml) for 16 h at 37.degree. C acquire increased susceptibility to complement and cell-dependent lysis mediated by monoclonal antibodies to HLA-A,B antigens and to human .beta.2-microglobulin but did not change in their susceptibility to immune lysis mediated by monoclonal antibodies to human Ia-like antigens. Changes in susceptibility to immune lysis of interferon-treated lymphoid cells are likely to reflect changes in antigen density, since binding assays with monoclonal antibodies and quantitative absorption assays with alloantisera showed that the expression of HLA-A,B antigens and .beta.2-microglobulin is significantly increased on interferon-treated lymphoid cells; that of Ia-like antigens is not changed.